Wire matrix printers utilizing multiple columns of print wires which may be selectively positioned to provide either high or near letter quality printing mode or high speed or data quality printing mode are well known in the art. Various means of positioning the columns is disclosed in U.S. Pat. Nos. 4,010,835; 4,400,101; and 4,470,713.
When print wires in one column are aligned with the corresponding wires in another column, high speed or data quality printing is obtained since it is possible to double the number of dots or points imprinted by the wires on the same line per unit of time as compared with imprints produced by a single column of prints wires.
When the print wires in one column are staggered in relationship to the wires in another column, the printing speed remains the same as if there was only a single column of wires, but the quality of printing is substantially improved over the high speed or data printing mode since it is possible to obtain overlaps of the dots or points imprinted by the wires thereby producing an improved appearance since the overlapping dots create a substantially continuous line of printing.
While the above identified Letters Patent provide various devices for shifting the print wires in different columns from high speed to high quality mode, and vice-versa, none of them discloses a simple, convenient device, having but a few parts, for on line shifting from one mode to the other employing minimum of movement and thereby greatly reducing the wear on the print wires.